I think that has to been an easier way to connect to other tennis people. I know some people get a discussion board going to find someone to hit with..but I think there should be that added organization. What if...
You went on the discussion board and started a thread saying as an example (Checking-in: Aug, 11th, 2011, Thursday. Ready to play at 5:30 pm ) That tells anyone else looking to hit that day you're available to play that day and what time, now it's just about contacting that person and the logistics of where. It was just a thought.
Or.. What if...
You had a calendar for each group and you put your availability for the week and it had your name on it so you can click on a person looking to hit on those days/times. Ex. (see below)
MON TUES WED THURS FRI SAT SUN
Julie 8:30 - 11:30 Julie 8:30 - 11:30
Mary 8am-11am Mary 8am-11am Mary 8am-11am Mary 8am-11am
Paul 4-10 pm Paul 4-10 pm
John 5-10 pm john 5-10 pm